It is proposed to investigate (1) the influence of the solvent on the conformational behavior of LSD and its derivatives; and (2) the effect of the structural flexibility. In addition, it is also proposed to calculate the dipole moment and polarizability tensors. Furthermore, it is also intended to describe the receptor essential conformations and to characterize the receptor site(s) in terms geometry and various forces responsible for the drug-receptor interactions. It is suggested to use the reaction field theory in conjunction with the empirical method in accomplishing the above mentioned task.